This invention relates to a filling device for a machine for filling containers with a filling product, in particular a food product, as well as a corresponding machine for filling. This invention relates more particularly to a filling device provided with a flow regulation system for the filling of containers, such as bottles or jars, with any sort of products, liquid to viscous, in particular with products that tend to foam and/or products that contain particles and/or pieces.
Machines for filling are known, in particular of the rotary type, comprising a rotating carrousel with a support structure carrying a tank of filling product and a plurality of filling devices. Each filling device conventionally comprises a filling spout, or dosing spout, a feed duct connecting the tank to the filling spout in order to feed the filling spout with filling product, and dosing means in order to deliver a determined quantity of filling product into each container brought under the filling spout. The filling spout is conventionally formed by a tubular body having an internal passage with longitudinal axis, an open lower axial end constituting the outlet orifice of the spout, and a feed orifice connected to the tank by the feed duct. The dosing means include a blocking system comprising a valve mounted mobile in said tubular body, and a valve actuating system for the longitudinal movement of said valve between a closed position in order to close the outlet orifice and an open position. The valve actuating system conventionally comprises a cylinder of which the rod passes through an open upper end of the tubular body of the spout, with the valve being fixed to the cylinder rod.
For the dosing of the product, it may be necessary to carry out the end of dosing at a low flow-rate, and this for multiple reasons: dosing precision, low free volume in the neck, foaming product, etc. For foaming products, milk in particular, it is necessary to carry out the start of dosing at a low flow-rate in order to limit the formation of foam. For semi-liquid products, this low flow-rate function can be created, without disturbing the flow, by retaining a cylindrical stream, by adjusting the position of the valve in order to reduce the opening of the dosing spout.
For liquid products, this solution cannot be applied, as the stream at the output of the dosing spout is at an accelerated speed, it has a direction that is instable, deformed and turbulent, which causes splashes and favours the formation of foam.
In order to stabilise the stream, several stacked grilles are conventionally added on the outlet orifice.
These grilles are prohibited for reasons of hygiene in the case of sensitive products such as milk where they cannot be correctly cleaned in place, and cannot be used in the case of products with particles and/or pieces. Another solution consists in providing a second seat in the filling spout cooperating with a tapered portion of the rod connected to the valve in order to limit the flow rate upstream of the valve. This solution is satisfactory but cannot be used in the case of products with pieces.